We have used information from the National Center for Health Statistics (NCHS) and Bureau of the Census to create a comprehensive data base concerning mortality and population information at the county level. Data are available, 1950-1981, for cancer mortality, and 1965-78, for deaths from other causes. Population data will be extended and corrected when the 1980 census data become available. Three-dimensional graphs employing these data are on example of the value of the data collection. Under development are systems for mapping counties in black-and-white, for projecting cancer mortality in coming decades, and for grouping counties by economic subregions.